This is a randomized, double-blind, placebo-controlled, three-period, multi-center clinical trial. Following a Screening and Qualification Period and a two-week Washout Period (for those subjects entering the study on a phosphate binder), eligible subjects will be randomized in a 1:1 ratio to receive either KRX-0502 (ferric citrate) or placebo for up to approximately 12 weeks. The purpose of this study is to determine if KRX-0502 (ferric citrate) is a safe and effective treatment for the management of serum phosphorus levels and iron deficiency in anemic CKD subjects not on dialysis.